Production of motor fuel



H. v. A'rwELL Er A1.

. PRODUCTION OF MOTOR FUEL May 16, 1939.

Filed Jan. 9, 193s Patented May 16, 1939 UNITED STATESPATENT oFF-ICE PRODUCTION F- MOTGR FUEL Harold V. Atwell, White Plains, and Malvin R. Mandelbaum, New York, N. Y., assignors to Process Management Company, Inc., New York, N. Y., a corporation of Delaware Application January 9, 1936, VSerial No. 58,270

4 Claims. (Cl. 196-9) i Our invention relates to the production of lowa yield of motor `fuel which could not be obboiling hydrocarbon oils suitable for use as motor tained were the hydrogen and methane retained fuel from relatively high-boiling hydrocarbon oil in the recycledgases. and normally gaseous hydrocarbons. We have observed that it is highly desirable 5 In cracking relatively heavy oil, the products, that means should be afforded whereby norll5 in addition to such coke or carbon as may be Inally gaseous materials of an oleiinic character formed, ordinarily comprise constituents both may be afforded an opportunity to react with heavier and lighter than the original charging or in the presence of hydrocarbon oils of parstock, ranging through residualoils or tars, gas aflinic character and, conversely, wherebyI noroils and kerosenes, gasoline and gases. The commally gaseous parans may be afforded an op- 10i position of the gases will vary considerably in portunity to react with or in the presence of accordance with the particular conditions of ophydrocarbon oil constituents of a non-paranicv eration, but the gases ordinarily include hydrocharacter. It may be observed at this point that gen, methane, other parainic constituents, such the lower boiling gases are less susceptible to as ethane, propane and butanes, and `varying treatment and, as will be explained hereinbelow, 15 amounts of olenic constituents, such as ethylit is ordinarily desirable to remove methane from ene, propylene and butylenes. It was suggested the paramnic gases and sometimes ethane as quite early in the development of the cracking wel1,whereas ethylene may similarly be removed art that a portion or all o`f these gases should from the olefinic gases before reaction. be re-circulated in the cracking process with the If mixed parainic and olefinic gases are re-` thought that by reason of some sort of mass acted with mixed parafnic and non-paranic action effect or the like, the retention of the oils, the concentration effects tend to reduce the gases in the stream would reduce the amount extent of inter-reaction and conversion taking of gases formed. However, this result was not place. Therefore, our invention contemplates y obtained to any substantial degree. More resegregating the paralnic and non-paraftlnic 25 cently, with the development of gas polymeriza- Constituents of hydrocarbon oil and hydrocarbon tion methods, it has been suggested that the gases and effecting reaction between olenc gases cracking gases should be freed from hydrogen and p'araiinic oil in one stage and reaction beand methane and the remaining fractionated tween parainic gases and non-parailinic oil in vgases be returned to the oil cracking operation. a separate stage, whereby a more complete de- 30 Under such conditions, polymerization or congree of inter-reaction may be obtained. version of the olenic constituents of the gases We do notconcern ourselves with the exact is actually observed to some extent but the yields mechanism of this reaction andV are content to obtained are susceptible to further improvement. state that reactions of this type can be effected It is, therefore, .an object of our invention to to a worthwhile extent when beneficially inu- 35 provide a process for the production'of motor encedby concentration factors. According to fuel by reaction between normally 'liquid and the views of some investigators, alkylation takes gaseous hydrocarbon materials that shall be place. Others have suggested that the `energy more effective than the methods previously sug- 4liberated by the olenic or unsaturated constitugested, ltogether with such additional operative ents causes the decomposition and resultant` 40 advantages and improvements as may hereinpolymerization or alkylation ofthe paraflinic after be found to obtain. constituents, While still other investigators have y It has been observed that, under elevated temsuggested that free radicals produced by the de- 'perature and pressure and especially in the prescomposition of the more easily decomposable ence of certain catalysts, reactions between oleclass of constituents exert what may be genns and paralns or between paramns and other erally termed an activating effect upon the non-parafilnic constituents, or the products of conversion of the remaining constituents. But, decomposition thereof, may'take place to a conin any event, it is our conception that whatever siderable extent but vthe extent to which these the mechanism of the reaction, it is beneficially reactions take place is influenced to a marked influenced by conducting the reaction under such 50 degree by the concentrations of the respective conditions that /the parafhnic or olenic conconstituents. This is borne out by the fact .that stituents of the gas in any particular reaction 'the removalV of hydrogen and methane `from stage are relatively free from other gaseous concracking plant gases to be `recycled in an oil stituents of the opposite type,`respectively, and cracking operation'makes it possible to obtain the individual types of constituents of the oil 55 y set forth and understood, we now describe, with reference to the drawing accompanying and forming a part of this specification, various preferred forms and manners in which our invention may be practiced and embodied.

In this drawing the single ligure is a more or less diagrammatical view of a system in which the process of our invention may be carried out, individual units thereof being shown in a more or less conventional manner. Referring now to this figure, a hydrocarbon oil suitable for conversion to lower boiling constituents and which may comprise a gas oil, a reduced crude or even a naphtha is delivered through a line I having a pump 2 to a solvent extraction unit of conventional type wherein the oil is treated with a suitable solvent to separate it into a parafnic fraction and a non-parafflnic fraction. Various solvents, such as liquefied sulphur dioxide, furfural, dichlor diethyl ether, phenols and other solvents known in the art, may be employed for this purpose. Various specific manners of obtaining the separation into various paraiiinic and non-parafnic constituents are known in the art. In any event, a parafflnic oil fraction is removed from the unit 3 through the line 4 while a non-parafiinic fraction is removed from the unit 3 through a line 5. It will be understood that the parafnic fraction may not be entirely free of nonparafiinic constituents and vice versa but, in any event, the separation is carried out as completely as possible under existing conditions and that, in any event, a materially greater concentration of parafiinic constituents, on thev one hand, and non-parafflnic constituents, on the other, obtains in the two fractions removed at 4 and 5, as compared with the original charging stock introduced at I. Where oil of a very highly or wholly parafiinic nature is available without recourse to solvent extraction methods, such oil may be introduced to the line 4 through a line 6 having a pump 'I while oilfrom any outside source which is substantially free from paraifnic constituents or, in any event, is very highly concentrated in non-paraiiinic cons tuents may be introduced to the line 5 throu a line 8 having a pump 9. 'By means of a pump II located in the line 4, paramnicoil is delivered to a furnace I2 which may be of any desired form of construction but will ordinarily comprise what is generally known in the art as a tube still'and wherein the oil is heated to an elevated temperature and pressure effective to promote conversion in the presence of olenic gas. Such oleflnic gas may be added from any suitable outside source through a line I3 having a pump or compressor I4 or by means of a line` I5, a line I6 or a line I'I. The source of the gases introduced through the lines I5, I6 and I1 or any of them will be set forth more clearly hereinbelow.

Within the furnace I2 the parafiinilc oil and the oleiinic gas are reacted under suitable conversion conditions which, in the absence of the cata lyst or in instances where catalytic effect is secondary, may comprise temperatures of 700 to 1,000 F. and pressures of from 500 to 3,000 lbs. per sq. in., the time of contact being relatively long and, in any event, adequate to carry the reactions to the desired extent. With catalysts of a more highly active natur/e, such as sodium aluminum chloride, and catalysts of the general type of adsorbent clays, such as fullers earth and the like, somewhat lower temperatures of 500 to 700 F. and pressures of 300 to 1,000 lbs. per sq. in. may be suitable, while, with still more active catalysts, such as phosphoric acid, aluminum chloride and boron fluoride, still lower temperatures and pressures of, for example, from to 500 F. and 100 to 500 lbs. per sq. in., may be emloyed and activators, such as hydrochloric acid and water vapor, may sometimes beemployed to good eifect. It will be understood, however, that while we have given the above temperature and pressure ranges as being those which we believe to be more suitable, it is contemplated that ourvariations therefrom may be resorted to under individual conditions of operation and charging stocks.

After conversion, the highly` heated products pass from the furnace I2 to a transfer line 2t wherein may be located a pressure reducing valve 2i to an evaporator 22 from which residual constituents are withdrawn through a valved line 23 while vaporous products pass through a vapor line 24 to a conventional fractionating tower 25. In passing to the tower 25, the vapors are subjected to fractional condensation for the separation of relatively clean heavy constituents of the nature of gas oil, such gas oil being removed from the bottom of the tower 25 through a valved line 26, The gas oil thus removed at 26 may, if desired, be recycled to the furnace i2 if of a suiiiciently paraiinic nature and, if not, may either be discarded from the system or cooled and returned to the solvent extraction unit 3 by means not shown'on the drawing for extraction and further utilization in the process.

In any event, the overhead vapors from the` pressure of, for example, about 200 lbs. per sq. in, and from which fixed gases comprising-hydrogen and methane, and in some instances, also ethane and ethylene, may be withdrawn through a valved line 30 and removed from the process while the condensate passes through a line 3|V wherein may be located a valve 32 and a pump 33 to a conventional rectifier or stabilizer 34 where the gasoline is fractionated to remove constituents intermediate between the desired gasoline fraction and fixed gases. Stabilized gasoline is withdrawn through a valved line 35 while overhead from the stabilizer 34 passes through aline 38 to acondenser 37 and thence to a pump or compressor 38. The overhead thus withdrawn will contain varying quantities of propane, propylene, butanes and butylenes, and may, -if desired, contain some ethane and ethylene.

It will be understood by those skilled in the art that in many cases, especially where the separation of the condensate is accomplished under relatively low pressure, these intermediate gaseous constituents may be withdrawn from the separator 29 together with the fixed gases and, in such instance, the gases withdrawn from the separator 29 will be fractionated in any suitable manner to remove hydrogen and methane and also ethane and ethylene to the extent desired, the object in any event being to'separate the light products of cracking into gasoline, a fixed gas fraction comprising largely` hydrogen and methane, and an intermediate fraction comprising `largely constituents from propylene to butane and it may be assumed that, in any event,

is preferably maintained under a relatively high 36 may be observed that .where solvents are eml the intermediate fraction is delivered to the pump or compressor 88.

Where desired, this fraction, 4however recovered, may be recycled to the furnace I2 through a 4unit to be described vher'embelow for conversion in the presence of non-paramnic oil, this lat- `ter procedure being followed wherever the fraction delivered to the pump 38 -is of a highly or wholly paraiinic nature.

As a still further alternative, the fraction def livered to the pump or compressor 38 may be l and thence through es line 45 to a gas separadelivered through a linef48 having a valve 44 tion unit 46 wherein the gases are treated for separation of paraiiinic and oleilnc constitu-l ents. Additiona hydrocarbon gas from any outside source, such, for example,A as natural vgas or cracking plant gas, mayalso be delivered to the gas separation unit4 46 through a line 41 having a pump or compressor 138 and a valve 48. The gas separation unit 46 is so conducted as aforesaid as to separate the gases into a highly paraiiinic fraction which is removed through a line 5l and a' highly olenic fraction removed through a line 52 while 'hydrogen and methane and, where desired, also ethane and ethylene may be removed if present in the gas delivered to the unit d6 through a valved line 58. In general, the gas separation unit 46 will be some'- what similar to the solvent extraction unit 3 and other fractionation or solvent extraction,

or both, methods may be employed although it ployed the initial` extraction step will ordinarily take place under such pressure as to maintain the gases in the liquid phase. As a suitable solvent for edecting separation betweenparamnc and olelnic constituents, we may mention furfural, the boiling point of which issuiilcientlyhlgh to facilitate separation of the extract from the solvent. Other solvents for the purpose include acetone, a solution of sulphur dioxide in a ketone, and solutions of mercury salts such as mercury sulphate, cuprous chloride and silver nitrate.

The oleiinio gases removed from therline 52 are compressed by means of a pump or compressor 53 to the requisite pressure and can then be returned through the line i5 to the furnace l2 for reaction in the manner hereinabove set forth while the paranic gas fraction removed at 5l may he delivered by means of a pump or cornpressor 5d for reaction with non-paraiilnic oil as will be set forth hereinbelow.

In reacting the non-parafilnic oil fraction removed at E or added to the line 8, essentiallythe same procedure may be followed as in the instance described hereinabove in which the paramnic oil fraction is reacted 'with olenic gases;` thus, this fraction may be delivered by means of a pump @d and a line'l to a furnace 62 where it is subjected to elevated temperature and pres sure with or without the presence of a catalyst under the'conditlons' already set forth hereinabove with respect to the operation taking place vin the furnace i2 and in the presence of a highly paraflinic gas added from any suitable' outside source through a line 63 having a pump or compressor 64 or through a line 4J o'r through a line l 65 communicating with the linev 5l and pump or compressor 54. Thus the residue gases in the operation taking place in the furnace l2 may struction. Gas oil is removed vfrom the bottom of the fractlonatingcolumn 15 through a valved line 16 and may be recycled to the furnace 62 or removed from the system or may be cooled and delivered to the solvent extraction unit 8 by means not shown on the drawing as in the case of the gas oil withdrawn through the line 26 from the fractionating column 25.

The'overhead vapors from the fractionatlng column l15 pass through a vapor line 11 toa condenser 18 and thence to a separator 19 from which xed gases are removed through valved line while condensate passes through a line 8| having a valve 82 and a pump 83 to a rectier or stabilizer 84. Stabilized gasoline is withdrawn from the stabilizer 84 through a valved line 85 while overhead comprising constituents intermediate between xed'gases and gasoline passes through a line 86 to a condenser 81 and thence to a' pump orcompressor 88.

As in the previous instance, the fractionation o the various products may' he variously accomplished but, in any event, theobject is to separate the fractions comprising largely hydrogen and methane, as well as ethane and ethylene, to the desired extent, the gasoline fraction and an intermediate fraction comprising largely propane, propylene, butanes and butylenes, but which may contain some ethane and ethylene, as desired.

This fraction, if sumciently concentrated in olenic constituents as distinguished from parailnic constituents, may he delivered from the pump or compressor 88 through the line i6 wherein may be located a valve 89' to the furnace l2 for reaction with the paranic oil introduced thereto or alternatively where the concentration of olens is not so great, this fraction is delivered through a line 90 having a valvel and thence through the line e5 to the gas separation unit d6. It will not ordinarily be desired to recycle gas from the compressor 86directly to the furnace 62.

If desired, the paraiiinic fraction delivered to the pump or Icompressor 88 may first be cracked at high temperatures and preferably low pressures to increase its content of olens before being delivered to the furnace I2. Thus, temperatures of from 1100 to 1500 F. and pressures offrom atmospheric to 200 lhs. per sq. in. are suitable for this purpose. Since this operation is well known as such in the art, no means for this purpose have been specifically illustrated in the drawing, it being understood that in this event the gases would be delivered from the pump 88 to a suitablecracking furnace and thence either .with or without cooling and fractionation to reabove with respect to various modifications and operative details,*it willl be understood by those skilled in the art that our invention is not limited to such, illustrative examples or details but may variously be practiced and embodied within the scope of the claims hereinafter made.

We claim:

l. The method of producing low-boiling hydrocarbon oil suitable for use as motor fuel from relatively heavy hydrocarbon oil and normally gaseous hydrocarbons which comprises separating said oil into a highly parailinic fraction relatively free of non-paraiiinic constituents and a nonparaillnic fraction relatively free of parafinic constituents, subjecting the highly paraiilnicfraction together with gases predominating in olenic constituents substantially free from hydrogen and 'methane to elevated pressure and temperature effective to promote decomposition of said oil fraction and polymerization of said oleiinic gas, fractionating the products to separate and recover materials higher boiling than the desired motor fuel product, normally gaseous hydrocarbons, and a gasoline fraction, separating gases predominating in parafilnic constituents from said normally gaseous hydrocarbons, separately subjecting said non-paraflinic oil fraction together with at least a portion of said gases predominating in paraiiinic constituents to elevated temperature and pressure effective to promote reaction between said normally gaseous hydrocarbons and said oil fraction, thereby producing gasoline, and 'fractionating the products to recover a second gasoline fraction therefrom.

2. The method of producing low-boiling hydrocarbon oil suitable for use as motor fuel from relatively heavy hydrocarbon oil and normally gaseous hydrocarbons which comprises separating said oil into a. highly parainic fraction relatively free of non-paraiiinlc constituents and a non-parafllnic fraction relatively free of paraffinic constituents, subjecting the highly parailinic fraction together'with gases predominating in oleiinic constituents substantially free from hydrogen and methane in a rst conversion zone to elevated pressure and temperature effective to promote decomposition o! said oil fraction and polymerization of said olennic gas, fractionating the products to separate and recover materials higher boiling than the desired motor fuel product, a normally gaseous hydrocarbon fraction, and a gasoline fraction, subjecting the nonparainic oil fraction together with gases predominating in paramnic constituents substantially free from hydrogen and methane in a second conversion zone to elevated temperature and pressure to effect conversion thereof to products including gasoline, fractionating the products to separate and recover materials higher boiling than the desired motor fuel product, a. second normally gaseous hydrocarbon fraction, and a second gasoline fraction, combining said normally gaseous hydrocarbon fractions and recovering therefrom gaseous fractions predominating, respectively, in olei'inic and paralnic constituents and relatively free of hydrogen and methane, and returning said last-mentioned fractions to said first and second conversion zones, respectively.

ing said oil into a highly parafilnic fraction rela-l tively free of non-parailinic constituents and a vnon-paraftlnic fraction relatively fre'e -of parafiinic constituents, separating said gaseous hydrocarbons into a fraction predominating in olenic constituents and a fraction predominating in parafnic constituents, subjecting the relatively high parafiinic oil fraction together with i said gas fraction predorninating in olens to elevated pressure and temperature effective to promote decomposition 0f said oil fraction and polymerization of said oleflnic gas, separately subjecting said non-paranic oil fraction together with said gas fraction predominating in parafns to elevated temperature and pressure to eifect decomposition of said oil fraction and conversion of said gas fraction, separately fractionating the products from each conversion operation to separately recover gasoline therefrom and normally gaseous hydrocarbons, fractionating the gaseous hydrocarbons to recover a vfraction predominating in olens and a fraction predominating in parafns, and returning said last-mentioned fractions to said first and second conversion zones, respectively.

4. The method of producing low-boiling hydrocarbon oil suitable for use as motor fuel which comprises subjecting a highly parailinic oil relatively free of non-parafilnic constituents together with gases predominatlng in olenic constituents and substantially free from hydrogen and methane in a first conversion zone to elevated pressure and temperature effective to promote decomposition of said oil and polymerization of vsaid olenic constituents, simultaneously and separately subjecting a non-parainic oil relatively free of paraflinic constituents together with gases predominating in paraiiinic constituents in a second conversion zone to elevated temperature and pressure to effect conversion thereof to products including gasoline, fractionating the products from said conversion zones to recover materials higher boiling than the desired motor fuel product, a gasoline fraction and normally gaseous hydrocarbons, re-

covering from normally gaseous hydrocarbons thus obtained-gaseous fractions predominating respectively in oleiinic and parailnic constituents and relatively free of hydrogen and methane and returning said last-mentioned fractions to said first and second conversion zones, respectively.

HAROLD V. A'IWELL. MALVIN R. MANDELBAUM. 

